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Contributions to Mineralogy and Petrology

, Volume 94, Issue 2, pp 253–261 | Cite as

Comments on “Composition and depth of origin of primary mid-ocean ridge basalts” by D.C. Presnall and J.D. Hoover

  • Don Elthon
  • D. C. Presnall
  • J. D. Hoover
Article

Abstract

Presnall and Hoover (1984), in their evaluation of the nature of primary mid-ocean ridge basalts (MORBs), concluded that earlier data suggesting many of the most primitive MORBs are derived from high-MgO (picritic) magmas are not valid. In reaching this conclusion, Presnall and Hoover (1984) ignore several important considerations regarding 1. analytical uncertainties, 2. TiO2abundances in MORBs, 3. least-squares calculations, 4. complex models of magmatic evolution and 5. enstatite saturation. I briefly discuss these points below.

Keywords

Mineral Resource Complex Model Analytical Uncertainty Early Data Enstatite 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Bence AE, Baylis DM, Bender JF, Grove TL (1979) Controls on the major and minor element chemistry of mid-ocean ridge basalts and glasses. In: Talwani M, Harrison CG, Hayes DE (eds) Deep drilling results in the Atlantic Ocean: Oceanic crust. Am Geophys Union, pp 331–341Google Scholar
  2. Bender JF, Hodges FN, Bence AE (1978) Petrogenesis of basalts from the project FAMOUS area: experimental study from 0 to 15 kbars. Earth Planet Sci Lett 41:277–302Google Scholar
  3. Bender JF, Langmuir CH, Hanson GN (1984) Petrogenesis of basalt glasses from the Tamayo region, East Pacific Rise. J Petrol 25:213–254Google Scholar
  4. Dungan MA, Rhodes JM (1978) Residual glasses and melt inclusions in basalts from DSDP Legs 45 and 46: evidence for magma mixing. Contrib Mineral Petrol 67:417–431Google Scholar
  5. Elthon D (1983) Isomolar and isostructural pseudo-liquidus phase diagrams for oceanic basalts. Am Mineral 68:506–511Google Scholar
  6. Elthon D, Casey JF (1985) The very depleted nature of certain primary mid-ocean ridge basalts. Geochim Cosmochim Acta 49:289–298Google Scholar
  7. Elthon D, Casey JF, Komor S (1982) Mineral chemistry of ultramafic cumulates from the North Arm Mountain massif of the Bay of Islands ophiolite: evidence for high-pressure crystal fractionation of oceanic basalts. J Geophys Res 87:8717–8734Google Scholar
  8. Elthon D, Casey JF, Komor S (1984) Cryptic mineral chemistry variations in a detailed traverse through the cumulate ultramafic rocks of the North Arm Mountain massif of the Bay of Islands ophiolite, Newfoundland. In: Gass IG, Lippard SJ, Shelton AW (eds) Ophiolites and oceanic lithosphere. Blackwell, London, pp 83–97Google Scholar
  9. Elthon D, Scarfe CM (1984) High-pressure phase equilibria of a high-magnesia basalt and the genesis of primary oceanic ba salts. Am Mineral 69:1–15Google Scholar
  10. Emmerman R, Puchelt H (1980) Major and trace element chemistry of basalts from Holes 417D and 418A, Deep Sea Drilling Project Legs 51–53. In: Donnelly T et al. (eds) Initial reports of the deep sea drilling project, US Government Printing Office 51,52,53:987–1000Google Scholar
  11. Fisk MR (1984) Depths and temperatures of mid-ocean ridge magma chambers and the composition of their source magmas. In: Gass IG, Lippard SJ, Shelton AW (eds) Ophiolites and oceanic lithosphere. Blackwell, London, pp 17–23Google Scholar
  12. Flower MFJ, Pritchard RG, Schmincke H-U, Robinson PT (1983) Geochemistry of basalts: Deep Sea Drilling Project Sites 482, 483 and 485 near the Tamayo Fracture Zone, Gulf of California. In: Lewis BTR et al. (eds) Initial reports of the Deep Sea Drilling Project, US Government Printing Office 65:559–578Google Scholar
  13. Fujii T, Bougault H (1983) Melting relations of a magnesian abyssal tholeiite and the origin of MORBs. Earth Planet Sci Lett 62:283–295Google Scholar
  14. Fujii T, Scarfe CM (1985) Composition of liquids coexisting with spinel lherzolite at 10 kbar and the genesis of MORBs. Contrib Mineral Petrol 90:18–28Google Scholar
  15. Green DH, Hibberson, Jaques A (1979) Petrogenesis of mid-ocean ridge basalts. In: McElhinney MW (ed) The earth: its origin, structure and evolution. Academic Press, London, pp 265–299Google Scholar
  16. Melson WG, Valuer TL, Wright TL, Byerly G, Nelen J (1976) Chemical diversity of abyssal volcanic glass erupted along Pacific, Atlantic, and Indian Ocean sea-floor spreading centers. In: Sutton GH, Manghnani MH, Moberly R (eds) The geophysics of the Pacific Ocean basin and its margins. Geophys Monogr Am Geophys Union 19:351–367Google Scholar
  17. O'Hara MJ (1968) The bearing of phase equilibria studies in synthetic and natural systems on the origin and evolution of basic and ultrabasic rocks. Earth Sci Rev 4:69–133Google Scholar
  18. O'Hara MJ (1977) Geochemical evolution during fractional crystallization of a periodically refilled magma chamber. Nature 266:503–507Google Scholar
  19. O'Hara MJ, Mathews RE (1981) Geochemical evolution in an advancing, periodically replenished, periodically tapped, continuously fractionated magma chamber. J Geol Soc London 138:237–277Google Scholar
  20. Presnall DC, Hoover JD (1984) Composition and depth of origin of primary mid-ocean ridge basalts. Contrib Mineral Petrol 87:170–178Google Scholar
  21. Presnall DC, Dixon JR, O'Donnell TH, Dixon SA (1979) Generation of mid-ocean ridge tholeiites. J Petrol 20:3–35Google Scholar
  22. Rhodes JM, Dungan MA, Blanchard DP, Long PE (1979) Magma mixing at mid-ocean ridges: evidence from basalts drilled near 22° N on the Mid-Atlantic Ridge. Tectonophysics 55:35–62Google Scholar
  23. Stolper E (1980) A phase diagram for mid-ocean ridge basalts: preliminary results and implications for petrogenesis. Contrib Mineral Petrol 74:13–27Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Don Elthon
    • 1
    • 2
  • D. C. Presnall
    • 3
  • J. D. Hoover
    • 4
  1. 1.Department of GeosciencesUniversity of HoustonUniversity Park, HoustonUSA
  2. 2.Lunar and Planetary InstituteHoustonUSA
  3. 3.Department of GeosciencesThe University of Texas at DallasRichardsonUSA
  4. 4.Department of Geological SciencesThe University of Texas at El PasoEl PasoUSA

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